A154000 Number of planar n X n X n binary triangular grids symmetric under 120 degree rotation with no more than 13 ones in any 5 X 5 X 5 subtriangle.

1, 2, 2, 4, 16, 31, 126, 1009, 3933, 31428, 512187, 4017316, 64213559, 2090787507, 32776879657, 1046731134966, 68125822829775, 2134091162950790, 136215005250379929, 17716724971218816648, 1109196056459852373561

Offset

0,2

Links

Table of n, a(n) for n=0..20.

Crossrefs

Sequence in context: A153994 A102864 A153997 * A154003 A291338 A326481

Adjacent sequences: A153997 A153998 A153999 * A154001 A154002 A154003

Keyword

nonn

Author

R. H. Hardin Jan 04 2009

Status

approved